Bacterial Species Research Articles

Formulation and Comparison of Herbal Gels Containing Essential oils and their Antimicrobial Evaluation.

The current study aimed to formulate and evaluate herbal gels con-taining essential oils for the treatment of infection caused by microbial species, i.e., S. au-reus, E. coli, P. aeruginosa, and B. subtilis. These species are also responsible for acne directly and indirectly. The gels were prepared using a gelling agent with 1% Carbopol-940, and they were further evaluated for physical appearance, drug content, in-vitro drug release, viscosity, extrudability, pH, and spreadability. Further, anti-microbial screening was done with various microbial species. Studies revealed that the gel was highly effective against the selected species ex-cept for the fungal strain. ZOI was observed ranging from 3.1 ± 0.01 mm to 13.4 ± 0.14 mm. The maximum ZOI was observed at 13.4 ± 0.14 mm against S. aureus. The physical properties of the gel satisfied the standard parameters. The prepared herbal gel was found to have highly promising activity against bacterial species associated with bacterial infection but in a dose-dependent manner. How-ever, more research is required.

The Influence of Dietary Supplementation with Dried Olive Pulp on Gut Microbiota, Production Performance, Egg Quality Traits, and Health of Laying Hens.

This study examines the dietary effect of dried olive pulp (OP) on the overall performance, egg quality, health, and gut microbiota of laying hens during a 36-week trial. A total of 180 Isa Brown layers, aged 23 weeks, were assigned to 15-floor pens and divided into three feeding groups (CON, OP4, and OP6) based on the dietary level of OP. Egg quality and biochemical parameters were assessed in 39- and 59-week-old hens. Fecal samples were collected for microbiota analysis. Data were analyzed with an Analysis of Variance. The percentage of broken eggshells was found to be 15-34% lower in the OP groups compared to the CON groups. At 59 weeks of age, a significant reduction in shell thickness was observed in the CON eggs compared to the OP eggs (p < 0.05). At 39 weeks of age, OP6 eggs had the darkest yolk color of all groups (p < 0.05). Fecal microbial diversity was affected only by hens' age. However, an enrichment in bacterial species belonging to the genera Megasphaera and Megamonas was found in the OP groups at 59 weeks of age. Our results demonstrate that OP feeding beneficially affects egg quality and promotes the proliferation of bacteria involved in the degradation of complex plant compounds, potentially contributing to the overall health of the gut microbiota.

Potential siderophore-dependent mutualism in the harmful dinoflagellate Alexandrium pacificum (Group IV) and bacterium Photobacterium sp. TY1-4 under iron-limited conditions

Specific bacterial species induce algal blooms by producing growth-promoting substances, such as siderophores, under iron-limited conditions. However, the molecular mechanisms underlying these effects remain poorly understood. This study investigates the interactions between the harmful dinoflagellate Alexandrium pacificum (Group IV) and siderophore-producing bacteria, with a focus on iron acquisition facilitated by bacterial siderophores. During algal bloom seasons in the South Sea of Korea, Photobacterium sp. TY1-4 was isolated, which enhances A. pacificum cell density under iron-deficient conditions, TY1-4 can use the sterile exudates from A. pacificum as the sole source of carbon, suggesting a mutualistic relationship. Transcriptomic and genomic analyses revealed siderophore-mediated redox-based signaling and non-reductive pathways enhancing iron bioavailability. Photobacterium sp. TY1-4 initiates siderophore production through quorum sensing, whereas A. pacificum utilizes specific receptors and transporters for hydroxamate-type siderophores (ApFHUA and ApFHUC) to uptake iron. Three redox key iron-uptake genes were also identified in A. pacificum: membrane-bound ferroxidase ApFET3, high-affinity iron permease ApFTR1, and ferric-chelate reductases/oxidoreductases ApFRE1, with transcription levels inversely related to bioavailable iron. Increased iron bioavailability mediated by siderophores alleviates iron stress in A. pacificum, supporting its growth in iron-scarce environments. Additionally, A. pacificum co-cultured with Photobacterium sp. TY1-4 synthesized high-toxicity STXs, including GTX4, GTX2, and STX. These findings highlight the critical role of bacterial siderophores in iron binding and their potential impact on harmful algal bloom dynamics.

Isolation and identification of major cockroaches associated pathogenic bacteria in Bonga town, Ethiopia

Cockroaches are a reservoir of various pathogenic microorganisms that pose a significant risk to public health because of unsanitary living spaces, poor waste management, inappropriate food storage, limitations of public health guidelines, and education on hygiene practices. The aim of this study was to isolate and identify major pathogenic bacteria associated with cockroaches in Bonga Town, Kaffa Zone. A total of 300 cockroaches were collected from Restaurants, Houses, and Hospitals, with 100 specimens from each location. The collected cockroaches were then subjected to microbiological analysis in the laboratory to identify potential bacterial pathogens. The cockroaches were killed using cotton-soaked chloroform, surface-sterilized using 70 % ethanol, and dissected aseptically. The cockroaches were added to 2 mL of sterile normal saline and shaken thoroughly for two minutes. The cockroaches were taken out of the tubes, and the remaining liquid was centrifuged at 2000 rpm for 10 minutes. The supernatants were then removed, and the remaining sediments were used for culture. In each tube, a fixed volume of 1 mL of the sediments was cultured on various culture media separately. Different species of bacteria with similar morphological characteristics were identified on the external and internal surfaces of the cockroaches. These results indicate the morphological characteristics of the colonies grown on each agar plate in different settings (Hospital, Restaurants and Households). The specific characteristics of the colonies can help in identifying different bacterial species. The isolated pathogens were then identified using standard microbiological techniques, including gram staining, morphology, microscopic slides, and biochemical tests. The results revealed the presence of bacterial pathogens, including E. coli, Salmonella, Pseudomonas, Staphylococcus spp., Shigella spp., and Proteus spp. The bacterial species were predominantly found in Households and Hospital areas, while fewer were found in restaurant areas. The presence of these pathogenic bacteria in cockroaches highlights the potential risk of food contamination and subsequent human diseases. Therefore, further analysis and characterization of these pathogenic bacteria should be done at the molecular level, and more clinical evaluation must be undertaken after the final identification and characterization.

Probiotic Properties of Lactobacilluscasei and L. plantarum Isolated From Overripe Avocado Pear

Probiotics have been researched for their benefit to gut health. Research for sources of probiotic bacteria has moved from milk to plants, as they have been found to be an inexhaustible source of lactic acid bacteria (LAB). The probiotic properties of lactic acid bacteria isolated from Over ripe Avocado pear on selected bacterial species were assessed. Fifty Unripe Avocado pears were purchased from different markets and allowed to ferment. Enumeration of the microorganisms and pure culture isolation were done on MRS agar supplemented with1.0% CaCO3 at 37 oC for 48 hours; using the pour plate and streak plate methods respectively. The isolates were identified based on their microscopic, macroscopic, biochemical and molecular characteristics. They include Lactobacillus casei and L. plantarum. LAB isolates were tested for their phenol tolerance, bile salt tolerance, acid tolerance and antimicrobial activity. All the isolates were tolerant to simulated gastrointestinal conditions. Growth of the isolates was observed at different temperature between 15 oC to 60 oC. They exhibited tolerance to phenol ranging from 0.085±0.01% to 2.40±0.02%. Tolerance to bile salt ranged from 1.06x101± 0.96x101 to 3.04x103±1.15x102. The acid tolerance level of the LAB obtained ranged from 2.98x102±1.30x102 to 8.78x102±2.22x102. Agar-well diffusion method was used to determine the antimicrobial susceptibility of the bacterial species. The test showed that the isolates were susceptible to the LAB isolates as zones of inhibition were observed. The inhibition zones diameter obtained ranged from 8.35±1.34mm to 13.77±2.21mm. Avocado pear, asides from their high nutritional content, also have the potential to serve as source of probiotic bacteria.

Regime difference between macrophyte and Cyanophyta dominance regulate microbial carbon sequestration mode in lake sediments

Different nutrient load in the lake ecosystems trigger the regime difference and change of predominant biotype. The regulation of carbon (C) sequestration mode in the lacustrine sediments in response to this process need prudent clarification. Fluorescence measurements and high-throughput sequencing for functional genes cbbL and cbbM encoding C-fixing bacteria genus were executed for sediments from two representative regimes dominated by macrophyte and Cyanophyta, respectively. The results showed that humic-like and fulvic-acid like materials dominated the dissolved organic matter (DOM) from the algae and macrophyte-dominated lake regions, respectively. Microbial assimilation played critical influence on C fixation into the sediments in both of the two regimes. However, higher diversity was detected in macrophyte-dominated regime compared to that in Cyanophyta-dominated regime, suggesting that moderate nutrient levels facilitated the species richness of bacteria encoding functional genes concerning C fixation. Bacterial species and diversities varied between two regimes including predominant and rare taxa, suggesting that community structure alteration due to regime difference triggered the regulation the C sequestration mode and stability. Predominant genera manipulated the abundance of C-fixing bacteria genes in response to the regulation of nutrient levels. Noted that rare genera also responded to the regime difference and played key role in C sequestration into lacustrine sediments. Our results suggest that more abundant macrophyte-dominated regime facilitated the C sequestration in the lake ecosystems for atmospheric C reduction.

Comparative in vitro Study of Antimicrobial, Antibiofilm and Quorum Sensing Inhibitory Activities of Hypericum calycinum L. and Parietaria officinalis L. Extracts

Aim: This study aims to elucidate both the anti-virulence and antimicrobial effects of ethanol extracts from Hypericum calycinum L. and Parietaria officinalis L. Material and Methods: Antimicrobial activity was evaluated using the well diffusion method against five bacteria and two yeast isolates involved in human urinary tract infections (UTIs). The potential of the extracts to inhibit quorum sensing (QS), was assessed using the biosensor strain Chromobacterium violaceum ATCC 12472. Additionally, the antibiofilm activities were investigated using a microplate biofilm assay on Escherichia coli and Pseudomonas aeruginosa. Results: H. calycinum exhibited the highest inhibitory effect at a concentration of 100 mg/mL against Candida albicans with an inhibition zone of 24.5±0.71 mm, while P. officinalis showed its highest effect at the same concentration against E. coli with an inhibition zone of 15.5±0.71 mm. Overall, H. calycinum demonstrated stronger antimicrobial activity compared to P. officinalis. Both plant extracts inhibited QS at similar levels, with inhibition zones ranging between 10-12 mm. The antibiofilm effect varied depending on the bacterial species, but notably, P. officinalis extract exhibited over 80% antibiofilm efficacy against E. coli at all concentrations. Conclusion: This study demonstrates that H. calycinum L. and P. officinalis L. are potent antimicrobial agents against UTI pathogens. While their anti-QS efficacy is not exceptional, the significant inhibition of E. coli biofilm formation underscores their potential as formidable agents. Designed as a fundamental study, it highlights the promising antimicrobial properties of these plant extracts and marks the first investigation into their capabilities as QS and biofilm-preventive agents.

Insights on mining the pangenome of Sphingobacterium thalpophilum NMS02 S296 from the resistant banana cultivar Pisang lilin confirms the antifungal action against Fusarium oxysporum f. sp. cubense.

Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), poses a significant global threat to banana cultivation. Conventional methods of disease management are increasingly challenged, thus making it necessary to explore alternative strategies. Bacterial endophytes, particularly from resistant genotypes, are gaining attention as potential biocontrol agents. Sphingobacterium thalpophilum, isolated from the resistant banana cultivar Pisang lilin (JALHSB010000001-JALHSB010000029), presents an intriguing prospect for combating Fusarium wilt. However, its underlying biocontrol mechanisms remain poorly understood. This study aimed to elucidate the antifungal efficacy of S. thalpophilum NMS02 S296 against Foc and explore its biocontrol mechanisms at the genomic level. Whole genome sequencing of S. thalpophilum NMS02 S296 was conducted using next-generation sequencing technologies and bioinformatics analyses were performed to identify genes associated with antifungal properties. In vitro assays were used to assess the inhibitory effects of the bacterial isolate on the mycelial growth of Foc. To explore the biomolecules responsible for the observed antagonistic activity, metabolites diffused into the agar at the zone of inhibition between Foc S16 and S. thalpophilum NMS02 S296 were extracted and identified. Whole genome sequencing revealed an array of genes encoding antifungal enzymes and secondary metabolites in S. thalpophilum NMS02 S296. In vitro experiments demonstrated significant inhibition of Foc mycelial growth by the bacterial endophyte. Comparative genomic analysis highlighted unique genomic features in S. thalpophilum linked to its biocontrol potential, setting it apart from other bacterial species. The study underscores the remarkable antifungal efficacy of S. thalpophilum NMS02 S296 against Fusarium wilt. The genetic basis for its biocontrol potential was elucidated through whole genome sequencing, shedding light on the mechanisms behind its antifungal activity. This study advanced our understanding of bacterial endophytes as biocontrol agents and offers a promising avenue for plant growth promotion towards sustainable strategies to mitigate Fusarium wilt in banana cultivation.

Specialized Listeria monocytogenes produce tailocins to provide a population-level competitive growth advantage.

Tailocins are phage tail-like bacteriocins produced by various bacterial species to kill kin competitors. Given that tailocin release is dependent upon cell lysis, regulation of tailocin production at the single-cell and population level remains unclear. Here we used flow cytometry, competition assays and structural characterization of tailocin production in a human bacterial pathogen, Listeria monocytogenes. We revealed that a specialized subpopulation, constituting less than 1% of the total bacterial population, differentiates to produce, assemble and store thousands of tailocin particles. Tailocins are packed in a highly ordered manner, clustered in a liquid crystalline phase that occupies a substantial volume of the cell. Tailocin production confers a competitive growth advantage for the rest of the population. This study provides molecular insights into tailocin production as a form of altruism, showing how cell specialization within bacterial populations can confer competitive advantages at the population level.

Identification and Antagonistic Potential of Bacillus atrophaeus against Wheat Crown Rot Caused by Fusarium pseudograminearum

Fusarium pseudograminearum (Fpg) is a significant pathogen responsible for fusarium crown rot (FCR) in wheat (Triticum aestivum L.), a disease with devastating impacts on crop yield. The utilization of biocontrol bacteria to combat fungal diseases in plants is a cost-effective, eco-friendly, and sustainable strategy. In this trial, an endophytic bacterial species, designated as SW, was isolated from the roots of wheat. The strain exhibited potent antagonistic effects against Fpg and reduced the FCR disease severity index by 76.07 ± 0.33% in a greenhouse pot trial. Here, 106 colony-forming units (CFUs)/mL of the SW strain was determined to be the minimum dose required to exhibit the antagonism against Fpg. The strain was identified as Bacillus atrophaeus using genome sequencing and comparison with type strains in the NCBI database. Whole-genome sequencing analysis revealed that SW harbors genes for siderophores, antifungal metabolites, and antibiotics, which are key contributors to its antagonistic activity. Additionally, the strain’s ability to utilize various carbon and nitrogen sources, successfully colonize wheat root tissues as an endophyte, and form biofilms are critical attributes for promoting plant growth. In summary, these findings demonstrate the ability of Bacillus atrophaeus to control FCR disease in wheat in a sustainable agricultural setting.

Search for Listeria spp. in fresh type sausages sold in the agreste region of Pernambuco and its importance for public health

Foodborne diseases (FBDs) are considered illnesses related to the ingestion of foods contaminated with physical, chemical, or pathogenic microorganisms. The genus Listeria spp. is responsible for the foodborne illness listeriosis. This pathology poses a significant public health risk due to its high mortality and sequelae, particularly affecting immunocompromised patients, pregnant women, the elderly, and children. The purpose of this study was to evaluate the presence of Listeria spp. in commercial fresh sausages. Eighteen samples of raw fresh sausages were collected and divided into three portions. Some were subjected to thermal treatments at two different temperatures (55ºC and 74ºC), while another portion remained raw, totaling 54 samples. Listeria monocytogenes and Listeria spp. research and isolation were conducted according to ISO 11290-1:2017. Biochemical tests were performed using the Gram staining methodology on characteristic strains. Additionally, moisture and ash determination and statistical analysis of the results were conducted. Among the 54 samples analyzed, approximately eight isolates showed colonies with characteristics suggestive of Listeria spp., thus not complying with the microbiological standards established by Resolution of the Collegiate Board (RDC) 331/2019 of the National Health Surveillance Agency (ANVISA). The presence of L. innocua and other pathogenic bacterial species in the samples is concerning, as there is a likelihood of microorganisms proliferating in the equipment and utensils used in sausage preparation, thus spreading pathogens to other products and increasing the risk of foodborne outbreaks and infections.

Reduction of Multispecies Biofilms on an Acrylic Denture Base Model by Antimicrobial Photodynamic Therapy Mediated by Natural Photosensitizers.

The aim of this study is to investigate the antimicrobial efficacy of antimicrobial photodynamic therapy (PDT) using natural photosensitizers (curcumin, riboflavin, and phycocyanin) and light-emitting diode (LED) irradiation against multispecies biofilms in an acrylic denture base model. Forty-five acrylic specimens were fabricated using heat-curing acrylic resin. The specimens were then infected with a mixed culture of bacterial and fungal species (including Streptococcus mutans, Streptococcus sanguinis, Candida albicans, and Candida glabrata) for 4 days. The acrylic discs were divided into nine groups, with each group containing five discs: control, 0.2% chlorhexidine, 5.25% sodium hypochlorite, curcumin, riboflavin, phycocyanin alone or along with LED. After treatment, the number of colony-forming units (CFUs) per milliliter was counted. In addition, the extent of biofilm degradation was assessed using the crystal violet staining method and scanning electron microscopy. All experimental groups exhibited a significant reduction in colony numbers for both bacterial and fungal species compared to the control (p < 0.001). The PDT groups exhibited a statistically significant reduction in colony counts for both bacteria and fungi compared to the photosensitizer-only groups. The results of this in vitro study show that PDT with natural photosensitizers and LED devices can effectively reduce the viability and eradicate the biofilm of microorganisms responsible for causing denture infections.

Characterization of the vaginal microbiota ininfertile women with repeated implantation failure.

Although the relationship between vaginal microorganisms and fertility has been well established, only few studies have investigated vaginal microorganisms in women undergoing in vitro fertilization (IVF). Our aim was to study the differences in vaginal microbiota between infertile women with repeated implantation failure (RIF) and those who achieved clinical pregnancy in their first frozen embryo transfer cycle. We compared the vaginal microbiota of patients with a history of RIF (n = 37) with that of the control group (n = 43). Following DNA extraction, metagenomic sequencing was employed for the analysis of alpha and beta diversities, distinctions in bacterial species, and the functional annotation of microbial genes. Furthermore, disparities between the two groups were revealed. Alpha diversity analysis revealed that the Shannon index was higher in the RIF group (P < 0.05). There were differences in the beta diversity between groups (P = 0.16). At the bacterial family level, the relative abundance of Actinomycetaceae (P = 0.013) and Ruminococcaceae (P = 0.013) were significantly higher in the RIF group. At the genus level, the abundances of Actinomyces (P = 0.028) and Subdoligranulum (P = 0.013) weresignificantly higher in the RIF group. At the species level, the abundances of Prevotella timonensis (P = 0.028), Lactobacillus jensenii (P = 0.049), and Subdoligranulum (P = 0.013) were significantly higher in the RIF group. Significant differences in family, genus, species, alpha and beta diversity were observed in the vaginal microbiota between groups. Notably, among these findings, the Subdoligranulum genus emerged as the most prominent correlating factor.

Bacteriological Quality Determination of Borehole Water Supply in Hostels of Rivers State University Main Campus, Port Harcourt, Nigeria

Water serves as a vehicle for the transmission of various diseases to man and animals, and have been associated with both acute and chronic health syndromes. This study was carried out to determine the bacteriological quality of borehole water supply in the Hostels of Rivers State University, Port Harcourt, Nigeria. Borehole water samples were collected from six (6) hostels for each study period, and subjected to standard bacteriological Procedures. Results obtained indicated that the highest mean total heterotrophic bacterial count of 3.6±1.7 X 105cfu/ml was recorded in the Hostel C water sample, while the least mean bacterial count of 5.5±0.35 X 104cfu/ml was observed in FCMB Hostel. The total coliform count had the highest value (3.3±3.82 X 104cfu/ml) recorded in Hostel D and the lowest value of 2.0±0.14 X 103cfu/ml was obtained in the Hostel H water sample. The faecal coliform count recorded the highest value in FCMB Hostel (1.5±0.71X 103 cfu/ml) and lowest in Hostel H (8.5±4.95 X 103 cfu/ml). The staphylococcal count was highest in Hostel B (8±9.9 X 104 cfu/ml) and lowest in Hostel C (0.6±0.57 X 104cfu/ml). Six bacterial species were identified, which included Bacillus spp (100%), Staphylococcus spp (100%), Pseudomonas spp (83.3%), Klebsiella spp. (66.6%), Salmonella spp (16.6%) and Escherichia coli (16.6%). Data obtained showed that all the isolates were biofilm producers, albeit at varying percentages, as 52.9%, 55.5%, 60%, 30%, 33.3%, and 100% of Bacillus spp, Staphylococcus spp., Pseudomonas spp., Klebsiella spp., Salmonella spp. and Escherichia coli, respectively were positive for biofilm formation. The hemolysis result indicated that 28.3%, 10%, and 61.7% of the isolates were alpha, beta and gamma hemolytic, respectively. The study indicated the presence of bacteria of public health importance, thereby, making the need for regular monitoring and treatment of these water sources very necessary to check bacterial proliferation and ensure continuous access to safe water in the hostels.

Biochar and wood vinegar altered the composition of inorganic phosphorus bacteria community in saline-alkali soils and promoted the bioavailability of phosphorus

As an important part of the ecosystem, saline-alkali soils are in urgent need of efficient and environmentally friendly soil conditioners. Biochar and wood vinegar are regarded as organic soil improvement and plant growth regulators to improve soil physicochemical properties and promote crop growth. However, the mechanism of how inorganic phosphorus bacteria increase phosphorus when biochar and wood vinegar applied to saline-alkali soils is not clear. Herein, the present study was designed to investigate the effects of biochar and wood vinegar with different rates on physicochemical properties of saline-alkali soils and inorganic phosphorus bacteria diversities and to discuss the mechanism of biochar and wood vinegar on available phosphorus by pot experiments. The application of biochar and wood vinegar exhibited an effect on the decrease in pH and salt contents and the increase in soil porosity, soil nutrients, and hundred-grain weight of rice. The 600 kg ha−1 biochar and 1800 kg ha−1 wood vinegar group showed the most significant increment in available phosphorus, alkaline phosphatase, acid phosphatase, and neutral phosphatase activities, with the increases of 49.24%, 40.35%, 48%, and 149%, respectively. The 600 kg ha−1 biochar and 1200 kg ha−1 wood vinegar group significantly enhanced microbial biomass phosphorus concentrations by 41.29%. Moreover, biochar and wood vinegar shifted inorganic phosphorus bacteria composition structure and promoted its diversities, more so at a higher rate of wood vinegar application. The dominant species of inorganic phosphorus bacteria were Proteobacteria, Gammaproteobacteria, Alphaproteobacteria, Pseudomonas, and Rhizobium in saline-alkali soils. The Alphaproteobacteria and Hydrogenophaga were the key microorganisms reducing pH and salt contents and increasing available phosphorus contents in saline-alkali soils. In conclusion, the application of biochar and wood vinegar was a useful strategy to improve saline-alkali soils.

Impact of dual Bt-transgenic maize (2A7) on soil microbial communities and enzyme activities: A comparative study with control variety Z58

The impacts of transgenic crops on soil microbiology and fertility are critical in determining their biosafety. While transgenic crops can alter soil microbes, their effects are often context-dependent; therefore, the ecological importance of these changes remains a topic of ongoing research. Using high-throughput sequencing, we investigated the effects of Bacillus thuringiensis (Bt) maize expressing the mcry1Ab and mcry2Ab genes (2A7) on soil nutrient dynamics, as well as the diversity and function of soil microbial communities, including bacteria and fungi, within different soil compartments. Our findings revealed a plant-shaped rhizosphere (RS) microbial community as a result of the selective recruitment of microorganisms from the surrounding environment. The transgene insertion had a significant impact on the RS niche, and several species eventually became associated with Z58 and 2A7 plants. For example, Neocosmospora rubicola fungal and Pantoea dispersa bacterial microorganisms were significantly decreased in the dual Bt-transgenic 2A7 rhizosphere but enriched in the Z58 rhizospheres. The activity of soil enzymes such as urease, invertase, and alkaline phosphatase was boosted by Bt-transgenic 2A7. LefSe analysis identified significant bacterial and fungal biomarker species that were responsible for the differential effects of Bt-transgenic 2A7 and control Z58 within rhizosphere soils. Mantel analysis further demonstrated that the root exudates of 2A7 altered nutrient-acquisition enzymes by influencing biomarker taxa. PICRUSt2 functional characterization revealed a significantly higher abundance of the phosphate-starvation-inducible protein in control Z58 than in Bt-transgenic 2A7. Furthermore, taxonomy, alpha (Shannon diversity), and beta diversity analyses all revealed niche-driven microbial profile differentiation. Niche partitioning also had a significant impact on N- and P-related COGs as well. Our findings suggests that Bt-transgenic 2A7 modulates rhizosphere microbial communities by affecting biomarker taxa and soil enzyme activity. These findings will promote sustainable agriculture practices by advancing our knowledge of the ecological effects of Bt crops on soil microbial communities.

Synthesis, antimicrobial activity, molecular docking and MD simulation studies, in silico ADME investigations and thermo-acoustic studies of heterocyclic dihydropyrimidine substituted 1,3,4-thiadiazole scaffolds

The connections between the chemical structures and antibacterial properties of different functional groups including organic molecules were examined in this study. we have synthesized a novel series of 1,3,4-thiadiazole hybrids (5a-o) based on 3,4-dihydropyrimidines. After an effective synthesis, the compounds' structure was confirmed by using spectrum techniques like IR, 1H NMR, 13C NMR, and mass spectrometry. Elemental analyses were performed on a Perkin-Elmer 2400 CHN analyzer and the resulting data were within the accepted range (± 0.40) of the calculated values. The in vitro antimicrobial activity of the compounds against a range of bacterial and fungal species. Compound 5i showed potent inhibitory effects against P. aeruginosa with MIC values of 12.5 μg/ml S. aureus and A.niger were positively affected by compound 5k with MIC values of 12.5 μg/ml and 50 μg/ml, respectively. Based on the results, compounds 5a and 5o have moderate activity against C.albicans and E. coli with MIC values of 50 μg/ml and 62.5 μg/ml respectively. Furthermore, molecular docking and molecular dynamics simulations were used to identify the most stable conformation of newly discovered inhibitors. Thermo-acoustical properties of derivatives 5k and 5l in DMSO and DMF solvent have been determined at three different atmospheric pressure temperatures (298.15, 308.15, and 318.15)K. The components of the liquid mixture's molecular interactions have been taken into account to explain these results. The acquired results are interpreted in terms of interactions between solutes and solvents, providing insight into the compounds' potential to form or disrupt structures in DMSO and DMF solutions.

Oral Fecal Microbiota Transplantation in Dogs with Tylosin-Responsive Enteropathy-A Proof-of-Concept Study.

A clinical trial was conducted to evaluate the effect of fecal microbiota transplantation (FMT) on the canine chronic enteropathy clinical activity index (CCECAI), fecal consistency, and microbiome of dogs with tylosin-responsive enteropathy (TRE). The trial consisted of four phases: (1) screening with discontinuation of tylosin for 4 weeks, (2) inclusion with re-introduction of tylosin for 3-7 days, (3) treatment with FMT/placebo for 4 weeks, and (4) post-treatment with follow-up for 4 weeks after treatment cessation. The study found that the treatment efficacy of FMT (71.4%) was slightly higher than that of placebo (50%), but this difference was not statistically significant due to underpowering. The most abundant bacterial species detected in the fecal microbiomes of dogs with TRE before FMT or placebo treatment were Blautia hansenii, Ruminococcus gnavus, Escherichia coli, Clostridium dakarense, Clostridium perfringens, Bacteroides vulgatus, and Faecalimonas umbilicata. After FMT, the microbiomes exhibited increases in Clostridium dakarense, Clostridium paraputrificum, and Butyricicoccus pullicaecorum. The microbiome alpha diversity of TRE dogs was lower when on tylosin treatment compared to healthy dogs, but it increased after treatment in both the FMT and placebo groups. Comparisons with the stool donor showed that, on average, 30.4% of donor strains were engrafted in FMT recipients, with the most common strains being several Blautia sp., Ruminococcus gnavus, unclassified Lachnoclostridium, Collinsella intestinalis, and Fournierella massiliensis.

RfaH contributes to maximal colonization and full virulence of hypervirulent Klebsiella pneumoniae.

Hypervirulent K. pneumoniae (hvKp) have emerged as clinically important pathogens, posing a serious threat to human health. RfaH, a transcriptional elongation factor, has been regarded as implicated in facilitating the transcription of long virulence operons in certain bacterial species. In K. pneumoniae, RfaH plays a vital role in promoting CPS synthesis and hypermucoviscosity, as well as mediating bacterial fitness during lung infection. In this study, we aim to conduct a systematic investigation of the roles of rfaH in the survival, dissemination, and colonization of hvKp through in vitro and in vivo assays. We found that bacterial cells and colonies displayed capsule -deficient phenotypes subsequent to the deletion of rfaH in K. pneumoniae NTUH-K2044. We confirmed that rfaH is required for the synthesis of capsule and lipopolysaccharide (LPS) by positively regulating the expression of CPS and LPS gene clusters. We found that the ΔrfaH mutant led to a significantly decreased mortality of K. pneumoniae in a mouse intraperitoneal infection model. We further demonstrated that the absence of rfaH was associated with slower bacterial growth under conditions of low nutrition or iron limitation. ΔrfaH displayed reduced survival rates in the presence of human serum. Besides, the engulfment of the ΔrfaH mutant was significantly higher than that of NTUH-K2044 by macrophages in vivo, indicating an indispensable role of RfaH in the phagocytosis resistance of hvKp in mice. Both mouse intranasal and intraperitoneal infection models revealed a higher bacterial clearance rate of ΔrfaH in lungs, livers, and spleens of mice compared to its wild type, suggesting an important role of RfaH in the bacterial survival, dissemination, and colonization of hvKp in vivo. Histopathological results supported that RfaH contributes to the pathogenicity of hvKp in mice. In conclusion, our study demonstrates crucial roles of RfaH in the survival, colonization and full virulence of hvKp, which provides several implications for the development of RfaH as an antibacterial target.

The developing pig respiratory microbiome harbors strains antagonistic to common respiratory pathogens.

Our study on the nasal microbiota development in piglets across farms in three European countries found that the microbiomes developed similarly in all locations. Additionally, we observed that the colonization of porcine pathogens was either positively or negatively associated with the presence of other bacterial species. These findings enhance our knowledge of co-colonizing species in the nasal cavity and the identified microbial interactions that can be explored for the development of interventions to control pathogens in porcine husbandry.